Various code edits:
* Implemented more HookCalls/MakeCalls/SafeWriteBatch in code.
* Moved return/jump address consts into their respective functions.
* Changed for-loop with iterators to use pre-increment.
* it changes the behavior of vanilla division operator to use signed
integer division. Before it used signed division for floats but
unsigned for integers.
Added a new "div" operator for unsigned integer division.
Moved mathematical script functions from Utils.cpp to new Math.cpp.
Added include guard to sfall.h and main.h in modders pack.
* calling endgame_movie now plays Movie11 or Movie12 depending on
the player's gender before the credits.
Added new flags to force_encounter_with_flags function.
Fixed the return value of charcode script function for characters in
the extended ASCII character set.
Rewrote set_dm/df_model, set_movie_path functions in C++.
* now the previous game mode can be checked with arg2 (#211)
Fixed GAMEMODECHANGE hook being triggered even when the game mode is not
changed.
Added 'SPECIAL' flag to the game mode functions (when switching from
DIALOG mode to BARTER).
Added "add_g_timer_event" and "remove_timer_event" script functions
for timed_event_p_proc in global scripts.
Fixed the check on the 'hidden' flag for previous commit.
NovaRain